Imagine a game of Dungeons & Dragons between Ellie from The Last of Us, Chun-Li from Street Fighter, Phoenix Wright from Ace Attorney, and Knuckles from Sonic the Hedgehog, with Overwatch’s McCree serving as dungeon master. While that scenario isn’t going to happen, a D&D campaign featuring the actors who lend their voices to those characters has been running for more than a year, attracting millions of viewers.

This article originally appeared in issue 285 of Game Informer.

The idea for Critical Role came from a game of Dungeons & Dragons that was started as a part of actor Liam O’Brien’s birthday celebration.

“Liam hadn’t played for a while, and I was running games,” says dungeon master Matthew Mercer. “I was like, ‘Hey man, if you want to play, let’s get some friends together,’ and so we did a one-off that turned into a campaign because everybody enjoyed themselves so much.”

Two years after that original game, TV and movie actress Ashley Johnson was shooting a web series called Spooked with actress Felicia Day, who was serving as executive producer. Day had recently co-founded a multimedia production company and commercial YouTube channel called Geek & Sundry. When Day noticed that Johnson had a copy of the D&D Player’s Handbook, she inquired about it, discovering Johnson was in a game with voice actors like Mercer (whom Day already knew). Day immediately asked the group to consider streaming it as a show on the channel.

While the idea was enticing, the group was concerned about taking their fun private game public. “Whenever you put something you love on the internet, there’s a very good chance that the internet is just going to tear you apart,” Mercer says. “So we had a real fear of it possibly tainting something that was so personal to us.”

Actress Marisha Ray echoes Mercer’s concern that it would destroy something they loved. “We all kind of took a vow at the table that if it wasn’t fun or it started compromising friendships or anything like that, that we would quit because it’s not worth it,” she says.

The group decided that if they were going to do it, then the format should provide as little disruption to the game flow as possible. Streaming on Geek & Sundry’s Twitch channel allowed for more free-form broadcasts before being archived on the YouTube channel, allowing great convenience and flexibility for the actors’ busy schedules.

Even though the format was set, the group was concerned that nobody would want to sit and watch people play Dungeons & Dragons for hours on end. “I think we just thought, ‘Well, whether or not people watch it, we’ll just try this and it’ll be an adventure, and if nobody watches it, we’ll just go back into the living room and play it,” Johnson says. “No big deal.'”

Despite the cast’s concerns, the show has resonated with fans of both tabletop games and the personalities. The initial episode has more than 2.5 million views on YouTube. Subsequent episodes have hundreds of thousands of views.

“The amazing thing is that it’s just blown up…not only for them being famous voice actors and amazing performers, but their love of D&D is so authentic,” Day says. “It’s really important to Geek & Sundry because it’s our flagship show, and support really anchors our live-stream programming that’s every single day.”

When I ask Mercer why he thinks it has resonated with so many people, he laughs in be wil derment. “I don’t know, man!” he says. “For a lot of older gamers who don’t have the time to play anymore because of work and family and responsibilities, this is their kind of game-by-proxy. They can listen to the adventure like a radio play, or watch it and still feel like this is part of their own adventure, so this is an outlet for that thing they miss.”

Travis Willingham, who plays Grog Strongjaw in the campaign, thinks one of the reasons it has been such a hit is because it helps further smash the early stereotypes associated with D&D. “There was a stigma for a long time for people who would play D&D – this basement-dwelling, mouth-breathing thing, and that’s not the case at all,” he says. “Our cast, the group of our friends is just made up of jocks and voice actors and directors and people who come from all backgrounds.”

With so many backgrounds in play, Critical Role is also helping to push away the outdated stereotype that D&D is a game only men play. “I think having this kind of visibility of seeing a game with a diverse cast with men and women and seeing the different aspects of the game that we bring to it makes a huge difference,” says actress Laura Bailey. “A lot of girls have written me on Twitter or on Facebook and said, ‘I never knew this was something I was allowed to do, and now that I’ve seen you guys playing, I’ve started actively finding a group. I went to a local game shop and I found people that are playing, and I’m now playing D&D regularly.'”

For Johnson, the misconception that the game was only for men prevented her from checking Dungeons & Dragons out sooner, but breaking down walls isn’t the only reason she’s glad Critical Role has strong female representation. “I think it definitely changes the dynamic of a game if you have a co-ed game, and I think it brings a lot of different arcs to the storyline that you’re playing,” she says.

The game has been running since March 2015, garnering hundreds of thousands of viewers every week, but one major mystery remains: What happens when this game ends? When I ask that question to each cast member, they all give some variation of Bailey’s answer – “I have no idea!”

“I know a lot of people are nervous about their characters dying,” Willingham says. “If I die, hopefully it’s in a blaze of glory, and maybe we’ll mourn my character for an episode and then some random-ass person comes walking into your world and joins the train.”

Though the mystery looms, Mercer is looking forward to whatever comes next. “Whoever survives will be sunsetted into legend,” he says. Then we’ll maybe take a little break, play a couple of small games in other systems to cleanse the palate, and maybe begin a whole new journey with level one characters.”

Johnson doesn’t know what’s next for Critical Role either, but she knows playing with this group of friends has given her a lifelong appreciation of Dungeons & Dragons. “If this game ends we would maybe start a new campaign or just go back to the living room and start from scratch,” she says. “I don’t feel like this group of people will ever stop playing D&D with each other, whether it’s this campaign or another one.”